Anyone who grew up in New York has a “remember when” story about the city’s restless landscape. Remember when Hudson Street in TriBeCa was stoplight-free? Or Harlem didn’t have a cineplex? Or a bike ride across the bridge to Williamsburg, Brooklyn, meant running a gauntlet of junkies? So much of the dynamic energy of New York is reflected in the ebb and flow of neighborhoods as artists, entrepreneurs, and other elements in the avant-garde of gentrification push into new territory and pioneer the transformation of run-down warehouse districts and urban wilderness into vibrant communities. Sometimes you know where you are in New York just because a neighborhood has consolidated sufficiently to achieve a signature look. Neat Bill Blass suits defined the Upper East Side of Babe Paley and company in the 1960’s as precisely as the asymmetrical hairdos and baggy, all-black Yohji Yamamoto suits did 1980’s SoHo, or today’s bearded L-train hipsters, accessorized with mini fedoras and fixie bikes, let you know you are in a Williamsburg your grandfather would not recognize.

I remember in the late 1970’s when West 57th Street between Fifth and Sixth Avenues was a no-man’s-land of construction sites, sickly health-food stores, and discount-clothing joints. It’s hard to imagine that the block where my brother and I relinquished our skateboards to a pair of muggers has now become a glamorous thoroughfare of high-end boutiques and hotels. What comes into fashion in New York can just as easily go out. It seems equally hard to imagine that there was a time when the now semi-suburbanized East Sixties were drop-dead cool: the fashion designer Halston was throwing decadent parties in his Paul Rudolph town house; Andy Warhol and Liza Minnelli were buying steaks at Albert & Sons, on Lexington Avenue, and the singles scene at places like Maxwell’s Plum inspired the movie Looking for Mr. Goodbar. Mention the East Sixties now and most people will mutter “nowhere to eat”—a wasteland.

At the moment, three of the most dynamic neighborhoods in New York City are TriBeCa, Harlem, and Williamsburg. Although vastly different in their histories and demographics, all three have blossomed into destinations with coveted addresses and trendy denizens while maintaining an authentic sense of community. In fact, you could say they’ve each become brands in their own right, clearly defined not only by physical boundaries but also by their architecture, attitude, fashion, and the ways they both embrace change—and resist it. If starving artists and farsighted businesspeople traditionally begin the process of change, real estate brokers often finish it.

TriBeCa: Hollywood East

“Everyone says New York is just a bunch of villages laid end to end,” says writer Karl Taro Greenfeld, whose novel Triburbia chronicles TriBeCa’s transformation from a cutting-edge no-man’s-land of famous clubs like Area on Hudson Street in the 1980’s and artists such as Richard Serra and Chuck Close in the 1970’s into a stomping ground for affluent celebrities including Meryl Streep and Gwyneth Paltrow. When my husband and I moved there in the late 1990’s, the neighborhood—with its cast-iron buildings and wide, cobblestoned streets—still felt like a village. It was a small community of mostly writers, artists, Hollywood types, and some prescient developers. There was a sense of separateness from the rest of New York City’s urban grid—mostly enforced by Canal Street and its rush-hour traffic. John F. Kennedy Jr. and his wife, Carolyn Bessette, were fixtures at the Hudson Street newsstand run by Mary and Fred Parvin, two early pioneers who were also considered the unofficial mayors of TriBeCa. Fred & Mary’s, as it was known, was a compulsory stop on every resident’s daily rounds, if not to buy the newspaper, then to catch up on gossip or catch a glimpse of Julia Roberts, Eric Bogosian, Edward Albee, or Adrian Lyne browsing the shelves and listening to Mary rant about George W. Bush and, later, the tragedy of 9/11. It was after the towers fell that TriBeCa began its reincarnation as an upscale neighborhood. Many of the original loft dwellers and young families fled, but even more residents stayed, determined to help the community and its small businesses survive.

Today, TriBeCa is having a second renaissance inspired by a new generation of change agents (the first being Drew Nieporent, Robert De Niro, and David Bouley, who transformed the place into a culinary destination in the 1980’s and 90’s with restaurants like Montrachet, Nobu, and Bouley). Now a younger group, including chef Andrew Carmellini of Locanda Verde and Matt Abramcyk of Smith & Mills, Warren 77, Tiny’s & the Bar Upstairs and, most recently, Super Linda, are bringing comfort food and trattoria style to the 19th-century Italianate and Beaux-Arts façades of the neighborhood. These days, instead of trucks backing into warehouse loading docks, you’re more likely to see Bugaboo strollers backed up alongside zinc-topped café tables outside Locanda Verde while young couples in Toms shoes and cuffed jeans scoop up Carmellini’s sheep-milk ricotta with squares of burned toast.

Before it was rezoned in the 1970’s, TriBeCa (for Triangle Below Canal Street) had been known since the early 1800’s as Washington Market, after the merchant-focused businesses and warehouses that stored produce, butter, eggs, and cheese and manufactured everything from soap to glass. Residents (what few there were: in 1970 only 370 people lived in TriBeCa) and passersby would smell the daily roasting coffee beans and desiccated coconuts. If a stray car ventured down Greenwich Street on a weekend, the driver was most likely lost. Once the merchants moved to Hunts Point, in the Bronx, and the artists began migrating in, the neighborhood was transformed from industrial zone to creative enclave. In the 1980’s, late-night restaurants like El Teddy’s and local clubs catered to a cool crowd of artists and aristos who would flock to Area for the openings of theme nights such as “Night” and “Gnarly” that featured everything from a masked welder to skateboard ramps.

Although Mary and Fred’s newsstand is long gone, many of the neighborhood’s industrial buildings still look the same, with steel loading bays and cast-iron flourishes. Parking lots have given way to three-bedroom condos and fancy establishments like Robert De Niro’s Greenwich Hotel. Whole Foods, Barnes & Noble, and Bed Bath & Beyond have opened. A favorite greasy spoon, Socrates, has been replaced by Tamarind Tribeca, a gigantic Michelin two-starred Indian restaurant serving $34 lobster masala. Celebrities are still drawn to TriBeCa, but that incognito, under-the-radar cool has been replaced by the pack of paparazzi chasing Tom Cruise or Brad Pitt into the caravan of Escalades purring outside De Niro’s hotel.

Still, some of TriBeCa’s pioneers are holding on to a certain mystique. Matt Abramcyk, who with his knit cap and beard looks more like a lumberjack than a savvy restaurateur, moved to the neighborhood after 9/11, when it was more affordable. “I grew up in New York City, and TriBeCa was always kind of mysterious,” says Abramcyk, whose wife, Nadine Ferber, is a co-owner of the TenOverTen nail salon above Super Linda. “The buildings were different, and it had a lot of potential to be exciting.” Back then fancy restaurants weren’t accessible, so Abramcyk had the idea to open smaller establishments with personality—what he calls “warm, neighborhoody environments,” where you could peel away the stories and textures from the bartenders and from the stuff on the walls. Smith & Mills, a former storage space and seafarer’s inn, was the perfect backdrop for such a place. The tiny interior, designed by Abramcyk, has a bathroom made out of a turn-of-the-century elevator with a flip-down sink from a Depression-era railway car. Tiny’s is modeled after Lower East Side butcher shops with handmade white ceramic tiles and 60-year-old wallpaper. At Super Linda, a Latin grill serving ceviche and grilled meat, the banquettes are covered in vintage burlap coffee-bean sacks, and Buenos Aires phone books from the 1940’s are piled on shelves behind the bar.

Old-timers who are prone to “There goes the neighborhood” reactions to the influx of bankers and Upper East Side types might balk at another new TriBeCa addition—an 1883 textile factory on Franklin Street that has been transformed into a Roman-style bathhouse where stressed-out visitors can soak the afternoon or evening away in tubs filled with red wine or cava for $450. A group of Spanish investors modeled Aire Ancient Baths after a similar outpost in Seville, Spain. The 16,000-square-foot space, which has been stripped down to the original columns, beams, and bricks, features 16th-century Spanish fountains and Moroccan lanterns and wooden benches made from original scaffolds of the Triboro Bridge.

Harlem: Uptown Renaissance

Like TriBeCa, Harlem is still defined by a strong sense of community and history, no matter how many developers slap together high-rise condos. “Harlem has always been a neighborhood. People say hello to each other,” says Bevy Smith, the founder of Dinner with Bevy, a networking series for VIP’s, who grew up on 150th Street and Frederick Douglass Boulevard. And that social, neighborhood familiarity is what ultimately inspired chef Marcus Samuelsson to open Red Rooster Harlem nearly two years ago, on Lenox Avenue between 125th and 126th Streets—a few blocks south of the tenement where Sammy Davis Jr. grew up and not far from the YMCA where Langston Hughes lived in the 1930’s.

“To me, Harlem is very Parisian, very social on the street, and with the big boulevards,” Samuelsson says. “I wanted a place with a large bar where you can be social. This is not the kind of place where you have to have your 8:15 reservation. Come in, take a book, talk to someone you’ve never talked to before.” What annoys Samuelsson is when people come up to Harlem but don’t interact with the people of Harlem. “I wanted this restaurant to be in front of the bus stop, so that the guy who gets off the bus sees the restaurant and says, ‘I want to take my girl there,’ ” he explains.

A Top Chef Master, author, and Obama favorite, Samuelsson has found his most important role in helping to rejuvenate this historic neighborhood where million-dollar condos are adjacent to some of the city’s poorest blocks. As a kid I remember taking the bus up through Harlem to school in the Bronx and passing blocks of abandoned 19th-century brownstones. You could still see the bones of once-beautiful buildings, but back then they had been taken over by squatters and crack dens, their windows boarded up, graffiti scrawled over doors. Certain blocks are still off-limits, still plagued by crime, but many of Harlem’s brownstones have been renovated and restored to their earlier grandeur.

Harlem’s latest renaissance—what was a literary and musical movement in the 1920’s and 30’s is now a culinary and real estate boom—respects the traditions that have made the neighborhood the historic center of African American culture. “If you’re going to move to Marcus Garvey Park, that’s lovely, but you have to know that on Saturday mornings there will be African drummers setting up there,” Smith says. You also have to know that Harlem residents always say Lenox and never Malcolm X Boulevard, and Lenox is like Fifth Avenue and Seventh Avenue is like the Champs-Élysées in a very traditional way—it’s the place to stroll on Easter Sunday. On a woven map hanging above the bookshelf at Red Rooster, Samuelsson identifies Harlem landmarks, including the Studio Museum in Harlem, where his friend, the stylish director and chief curator Thelma Golden, holds forth. Then there are Sylvia’s soul-food restaurant up the street and Parlor Entertainment at Marjorie Eliot’s, a free Sunday evening concert series in her northern Harlem home.

“I knew the place was changing ten years ago when I overheard developer Rodney Propp one morning in Settepani telling the owner he was investing in real estate up here,” says Elaine Griffin, an interior designer and author who lives near Marcus Garvey Park. Her instincts were right. Since then, movie theaters, Duane Reade drugstores, and banks have popped up. There’s a Target in East Harlem and an Aloft Hotel on Frederick Douglass Boulevard between West 123rd and 124th Streets. Frederick Douglass Boulevard between 110th Street and 125th Street is now known as Restaurant Row, with places like Lido, Five & Diamond Harlem, and Frederick Café Bistro packed on weekend nights. A new ramen place called Jin Ramen, a beer garden called Bier International, and a French bistro called Chez Lucienne all reflect Harlem’s influx of multicultural residents. According to the recent census reports, now there are more Hispanics, Caucasians, and Asians in greater Harlem than there are African Americans. Yet it is still the neighborhood’s history as the seat of African American intellectual culture that makes it one of New York City’s prime tourist destinations. Visitors—especially Europeans—head to 125th Street to sip Harlem Mules and listen to Roberta Flack or the Rakiem Walker Project at Ginny’s Supper Club downstairs at Red Rooster, or to attend Reverend Calvin O. Butts III’s service at the Abyssinian Baptist Church, on Odell Clark Place.

When Samuelsson opened Red Rooster, he was inspired by another groundbreaking restaurant, the Odeon, in TriBeCa. “That restaurant changed forever the relationship between restaurant and community,” Samuelsson says. “Anyone could feel comfortable there.” Indeed, when it opened on West Broadway in 1980, Odeon, with its mirrored mahogany bar, became a kind of clubhouse where everyone was welcome. The food was unpretentious and the atmosphere was unpredictable. You could be seated next to Jean-Michel Basquiat or Martin Scorsese. In many ways, Odeon became a model for the change-agent restaurants that would help gentrify other fringe areas of New York City over the coming decades.

Williamsburg: The New Brooklyn

Andrew Tarlow, an artist who waited tables at Odeon in the mid 1990’s, moved to Williamsburg 17 years ago for the cheap rent and abundant studio space, but he couldn’t find a convenient place to get a meal. Even the bodegas were off-limits, mostly because drug dealers ran them. So in 2000 Tarlow opened Diner, on Broadway in South Williamsburg, and served organic, locally sourced food in a simple setting. Like Samuelsson, he had been inspired by the power of restaurants such as Odeon to establish a neighborhood and bring together the community. “The idea was that anyone could come,” Tarlow says. He followed Diner’s success with Marlow & Sons, another restaurant and shop, and Marlow & Daughters, a butcher that serves locally sourced beef and poultry. Although he is loath to agree, Tarlow is considered the unofficial mayor of Williamsburg’s artisanal food movement. He’s also a great champion of the community, using craftsmen and resources from the area for most of his projects. The cramped shelves of Marlow & Sons are stocked with Mast Brothers chocolate bars (their factory is just a few blocks away), McClure’s pickles, and Goldie’s soap.

Last spring, in partnership with Australian hotelier Peter Lawrence and DUMBO developer Jed Walentas, Tarlow opened his fifth Brooklyn restaurant, Reynards, in the new $32 million Wythe Hotel, a 1901 former barrel factory on Williamsburg’s more industrial northern edge. Much like Tarlow’s restaurants, the Wythe Hotel has a very local vibe. Most of the interior wood in the original building was salvaged and used to create beds and ceilings. The wallpaper in each of the 72 rooms was custom-made by Flavor Paper, in Brooklyn’s Cobble Hill. The toiletries are from Goldie’s and the mini-bars offer fresh granola from Marlow & Sons, small-batch booze, and house-made ice cream. There’s a bar on the sixth floor with an enormous terrace and a killer view of the Manhattan skyline. Bands who come to play in the neighborhood or at the annual summer music festival can crash on the second or third floor, where rooms with floor-to-ceiling bunk beds go for $175.

Originally, Tarlow liked the site because it had a desolate feel, not unlike Broadway when he opened Diner. But in the time it’s taken them to renovate, the area has filled in with music halls like Brooklyn Bowl, a design studio that turns into a Swedish-inspired restaurant called Frej three nights a week, and another hotel, King & Grove Williamsburg, from the team behind hot spots in Miami and Montauk. When Tarlow first moved to Williamsburg, there were no amenities. In fact, it was cheaper to buy pressed white shirts from a thrift store than it was to take his shirts to be cleaned in another borough.

Although Bedford Avenue, the main artery of Williamsburg, is now lined with restaurants, nail salons, bodegas, and Laundromats, many more esoteric stores can be found on side streets stretching down toward the river. Moon River Chattel and Sprout Home on Grand Street sell refurbished antiques and do-it-yourself terrarium kits. At Pilgrim Surf & Supply, a new surf shop around the corner, owner Chris Gentile sells Andreini surfboards, M. Nii Makaha board shorts, and a dizzying array of DVD’s and books. Gentile, an artist, took over the former motorcycle shop last winter and built the interior out of reclaimed wood he found on site.

Everyone in Williamsburg seems to be making something—whether it’s fixed-gear bikes, organic soaps, or chocolate. Michael and Rick Mast of Mast Brothers Chocolate were among the first to support this idea of local manufacturing. In 2006, they began creating chocolate from scratch. Soon they were selling their handmade bars at markets and doing special orders for weddings. Now they have a booming chocolate business out of their North Third Street factory, where they roast, crack, and grind cocoa beans imported from Central and South America. Derek Herbster, a resident chocolate expert at Mast Brothers who has lived and worked in the area for two years, cannot get over the changes to Williamsburg. “It’s weird to me to live in the biggest city in the world and have it feel like a small town,” he says.

On an early Friday evening in June, I had dinner at Reynards with some friends. The cavernous bar room, with its black Thonet café chairs and exposed-brick walls, was already hopping with Brooklyn foodies dressed in floral-print minidresses, flip-flops, and shorts with plaid shirts. Was it possible that every diner in this restaurant was 26? Tarlow, in a cotton suit with too-short pants, was manning the maître d’s desk, smiling at drop-ins as he politely turned them away. A tattooed waiter with peroxide-blond hair explained that the menu changes every day and the water is carbonated in-house. The plainspoken menu, which includes bluefish, lobster served with snap peas and vanilla, and grilled chicken, belied the rich and delicious flavors of the seriously fresh food.

When Tarlow dropped by our table to chat, we pressed him on his idea to open a restaurant that was a strange juxtaposition of fine dining and neighborhood joint serving food grilled or baked in a wood-burning stove—“touched by fire,” as he put it. How had Tarlow known that Upper East Siders would trek all the way across the bridge for a meal? He shrugged. Many of the neighborhood’s pioneers, including Tarlow, have already fled to the more residential Greenpoint. Artists like Gentile have moved their studios to the Navy Yard. And when I asked Tarlow where he might venture for his next restaurant he shrugged and said, “the Upper East Side.” We all burst out laughing. “I’m not kidding,” he said with a sheepish smile. “It’s a wasteland.”